Nuclear Medicine imaging has been widely used to preoperatively image structures of interest for excisional biopsy. Radio-guided intraoperative procedures utilizing radiotracers have facilitated a cost-effective, highly specific means to locate suspect tissue and access it for pathologic analysis. The result of radio-guided surgery is increased tissue specificity obtained for biopsy, minimally accessed incisions, and the reduction of inpatient hospital utilization with an improved patient recovery. Nuclear medicine based surgical guidance with non-imaging gamma detector probes is gaining in acceptance and popularity. The main drawback of non-imaging guidance is the lack of ancillary information of the surveyed area, such as distinction between two neighboring radioactive regions, which can be overcome with an intraoperative imaging probe. Also, the highly penetrating gamma radiation arising from other parts of the body increases the background and limits the practical use of these probes. We propose to address these limitations by designing a new-generation intraoperative probe intended to rapidly image the tumor bed with short-range beta rays. This new design will be based on a solid-state, compact readout sensor coupled to a high resolution, high SNR converter. When developed, this detector will allow accurate delineation of the tumor, thus facilitating precise resection. PROPOSED COMMERCIAL APPLICATIONS: Advances in radiopharmaceuticals has dramatically escalated the use of intraoperative probes in surgery. The proposed research will provide a new class of digital imaging probes, which will exploit these advances allowing for complete and accurate tumor resection with enhanced quality of health care and increased lifespan of patients. This new imaging technology has enormous potential in both medical and non-medical applications. The estimated market size for probes is well over a hundred million dollars. A significant fraction of this market represents areas where the proposed technology will have a major impact.